Standard Test Method for Measuring Shear Properties of Structural Adhesives by the Modified-Rail Test

1.1 This test method describes equipment and procedures to measure the shear modulus and shear strength of adhesive layers between rigid adherends. The equipment may also be used for determining the adhesive's shear creep compliance, the effects of strain history such as cyclic loading upon shear properties, and a failure criteria for biaxial stress conditions such as shear plus tension and shear plus compression.

1.2 High-density wood shall be the preferred substrate. The practical upper limit on the shear modulus that can be measured is determined by the shear modulus of the adherends and by the strain measuring device. Thus, the practical limit of adhesive shear modulus that can be measured using high-density wood adherends is about 1 X 10 psi (690 MPa).

1.3 The range of specimen dimensions that can be tested are: width 0.0625 to 0.500 in. (1.59 to 12.70 mm), length 4 to 8 in. (102 to 203 mm), and adherend thickness 0.50 to 1.00 in. (13 to 25 mm). The standard specimen dimensions shall be: width 0.125 in. (3.18 mm), length 8 in. (203 mm), and adherend thickness 0.75 in. (19 mm). Bondline thicknesses from 0.006 to 0.125 in. (0.15 to 3.18 mm) may be tested.

1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.